Download department of commercial crops, fruits and forestry zanzibar

DEPARTMENT OF COMMERCIAL CROPS, FRUITS AND FORESTRY
ZANZIBAR
VEGETATION RECCONNAISSANCE SURVEY OF KIWENGWA FOREST RESERVE OF
ZANZIBAR - TANZANIA
BY: 1Kombo,YH, Said Juma, Said Fakih, Tahir Abass and Duncan Oliver
The Department of Commercial Crops, Fruits and forestry
Zanzibar.
2004
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Contacts:Kombo YH: Email: [email protected]; [email protected]. Webhttp://[email protected]; Mobile +255 713 459447
INTRODUCTION
Zanzibar is located in the Indian ocean, just off the coast of East Africa, lying at 390 East and 60 South
of Equator with an area of 2641. According to Tanzania Census (1988), Zanzibar inhabits 640,578
people of which 375,538 are in Unguja and 260,039 are in Pemba. The annual population growth rate
was estimated to be 3.3% and the estimated average population density is about 300 people per Km2.
The climate of Zanzibar is tropical and maritime, and follows the monsoon winds. The main rain
season (masika) occurs between March and June. The short rains (vuli), usually starts in October and
ends in December. However, some inter-monsoonal precipitation takes place. Record shows that one
fifth of total rainfalls between the rain seasons, which is dominated by a binomial rainfall pattern. The
average rainfall for the island is about 1500 mm per annum. February – March is the driest period of
the year with about 20mm of rainfall. The highest temperatures occur during the short dry season with
a maximum mean of 33oC in Unguja and 29oC in Pemba. The minimum temperatures for Unguja and
Pemba are 23.3oC and 21.1oC, respectively
Soils: The Zanzibar soils are mainly categorized into two classes; the shallow, acidic, infertile, rocky
coral rag soils in the east and deep, fertile soils in the west. Lager proportion of western side of the
islands has been overlain with alluvial sands, silts and clays with freely drained reddish soils formed
from these sediments termed "kichanga". Darker "kinongo" soils, derived from limestone parent
materials, are found towards east. The remaining "kinamo" heavy soil type is found in isolated areas
(Review Mission, 1991).
Agricultural sector contribute about 50% share of GDP and employs nearly 70% of labour force that
earns about 90% of export value. The contribution of the forestry sector to the national economy is not
calculated separately from the agricultural sector. It combines agriculture, livestock, forestry and
fisheries. The total land under agriculture and forestry is about 99%. Forestry woodlands cover about
16.2% of the total land, while grazing land and cultivated land cover 40.9% and 41.6%, respectively.
There are seven forest plantations in Zanzibar covering the total area of 12581 ha (5961 ha) Unguja and
2620 ha). Main plantation species include 57% Acacias (Acacia auriculiformis and A. Mangium), 24%
Casuarina equisetifolia, 16% Pinus caribaea and 3% of other species such as Tectona grandis and
Eucalyptus species and Pinus caribaea.
KIWENGWA FOREST RESERVE
Kiwengwa forest is situated in North Eastern Conner in the Northern region of Zanzibar main Island.
Unguja Island appear to have been once covered by dry evergreen and coral rag thickets. From 1970s,
the coral of eastern arc from Chwaka north wards have been seriously depleted (high demand of wood
resources and shifting cultivation).
Kiwengwa forest is the last remaining large patch of the forest that represent the biodiversity of the
area. Kiwengwa forest is an important depended by many communities of the north region (fuel wood,
medicinal plants and poles).It also important habitat that encompasses several Endemism and rare
species of both flora and fauna.
The forest attains the status of forest reserve since 2003 and covers an area of 3333 hackers. It is a long
stretch parallel to the eastern coast from Pongwe to north of Kiwengwa village
Kiwengwa forest is surrounded by several villages such as Kumba urembo, Cairo, Pongwe, Gulioni
Mgonjoni and Mchekeni.
OBJECTIVES
Kiwengwa forest is a recent gazzetted forest reserve with very few information on vegetation types and
species distribution. Since Kiwengwa forest is adjacent to tourism zones, thus the gathering of
information can also assists the tour guides once when tourism activities starts. Therefore this
vegetation reccoinnance survey has the following objectives;
-Identify vegetation types/habitats found in Kiwengwa forest.
-Explain the distribution of species, rare, and dominant species.
-Produce plant species list of Kiwengwa forest.
METHODOLOGY:
The already transect established to monitor red colobus monkey we re used to observes the vegetation
types and species found in the forest.
Using these lines, sport observation after every 200m.were taken for the types of vegetation, canopy
cover, averages height and diameter range of the trees. While walking in the transect new species not
found in each sport is listed. Also whenever change of vegetation habitat was experienced the record of
all above information and distance is noted. This is a quick observation procedure since there was a
limed time of four days for the field work.
RESULTS:
History shows that Kiwengwa forest is coral rag forest of high canopy with mature trees in most of its ,
but due to human activities such as fire ,shifting cultivation, cutting of fuel wood and building poles
resulted to different types of vegetations:
The vegetation types recognized during the study are:
1 Shrub land.
These types of vegetation is experienced in areas where shifting cultivation takes place in recent years
and areas with hash soil conditions which makes the growth difficulties. This seen in north western
parts, western central parts in Mgonjoni and kidutani and near Pongwe village.
The most common species found are Suregada zanzibarensis, Sorindeia madagascarensis, Eugenia
spp., Ficus sur, Dovyalis macrocalyx, Allopyllus, Flueggia virosa, Euclea racemosa, Macphersonia
gracilis, Psiadia arabica, Polysphaeria pervifolia,Annona senegalensis, Mallotus, Todalia, Vernonia,
Ozoro obovataa, Dodoneaviscosa, Clerodendron, Tarrena turrea, Terminalia boivinii, Strychnos
angolensis, Lannea, mystroxylon, and Encephalartos hildebrandtii.
The average height is about 4m. or less with canopy cover between 30-50%.
It is a secondary vegetation with less 10cm. Diameter at breast height.
2 Mixed thickets:
This is experienced in areas where the most interesting species have been cleared and leave thorny
trees , climbers and bush as a result it is difficult to pass through. This is experienced in Pongwe just
after bush vegetation in ward within a distance of about 600m., North Eastern side and narrow belt near
the road in the way from Kumba uremb towards Pongwe.
The average height is 7m. and canopy cover varies from 30- 60%. The common species here are:Rhus,
Diospyros, Polyspheria, Psychotria bibracteatum, Eugenia, macphasornia, Mimusopsis fruticosa,
Mystroxylon, maytenus, Euclea, ,olea woodiana, Encephalartos and climbers.
3. Low coral rag:
This is experienced in west and east sides of the forest after either thicket or shrub vegetations inwards
from Kumba urembo to Pongwe. Some times is alternating with high coral rag. The average height
range is 8-12m.and canopy cover is between50- 60%.
The dominant species are Encephalartos, Euclea, Diospyros, Macphersonia, Eugenia, Mystroxylon,
Psychotria bibracteatum. The regeneration is high and the forest has two storeys.
4. High coral rag:
This is a long stretch from Kumba urembo south wards to Pongwe at the middle of the forest. The
average height is between 15 –20m and canopy covers over 70% except in disturbed areas. The
diameter at breast height reaches up to 30cm.The dominant tree species include; Eugenia spp,
Encephalartus, Diospyros, Macpharsonia, Mystroxylon, Ozoroa, terminalia boivanii, and Mimusopsis
fruticosa. The forest is open, with storeys and the regeneration is low, thus it is easy to pass through.
5. Others vegetation types:
These are the open patches resulted from fire which is dominated by ferns and pioneer species such as
Trema orientalis , Vernonia spp and Flueggia virosa.
DISCUSSION:
From the result is shown that the vegetation near to human settlement or near the roads the vegetation
are much affected , low in height and diameter, this is due to the fact that it is easy to transport material
to the road and short distance walking to their shamba.
The shrub vegetation are seen most in the west side and the thicket is seen in the east, this implies that
the use of the forest differs between two sides, shifting cultivation is more in the west but in east the
forest is probably affected by fuel wood and building poles cutting as most of people in eastern sides
engage in fishing activities.
There is high species diversity in shrub vegetation than in any other type of vegetation from pioneer to
forest species and looks like an ecotone between the forests to agricultural areas.
There are species with wide distribution in all vegetation types such as Encephalartos hilderbratii,
Eugenia spp, Diospyros consolatae, Euclea racemosa, Mystroxylon aethiopicum, Psychotria
bibracteatum and Olea woodiana. Despites of distributed throughout the forest the Olea is more
dominant in the north and Diospyros, Eugenia and Encephalartos are more in the southern part of the
forest.
There a re also species which only seen in the northern part and not in the south such as Teclea
simplicifolia, grewia spp, syzygium cumini, Sansevieria conspicua, Blghia unijugata and Bysocarpus
orientalis
The rare species includes Pittosporum viridiflorum, Teclea simplicifolia, Steculia rhynchocarpa, and
Blighia unijugata and sansevieria conspicua.
Despite of being rare Pittosporum is also threatened and few individual remain as it has high medical
value also is a common food species for the adder’s duiker. Eugenia is only restricted in Unguja and
Pemba. Teclea have bee only recorded at Jozani, Misali and Msitu Mkuu forest throughout Zanzibar.
A full list of species list is attached as appendix.
RECOMMENDATIONS
-what has done in this study is only a reconnaissance survey it is obviously more species can be
identified if a systematic vegetation analysis be done.
-Many part of the forest have been changed from its original nature due to human activities and signs
of forest cutting still exist in all vegetation areas, thus effort are needed to conserve the remaining
vegetation with emphasis rare and endemic species.
-Because Kiwengwa forest is surrounded with communities that needs the resources from the forest
participatory conservation can be the best option for sustainable utilization of the forest
List of plant species from Kiwengwa forest.
Family
Euph
“
“
“
“
“
“
“
“
Eben
“
“
Cyc
Comp.
“
Comb.
“
Cela.
“
Big.
Aral.
Ann.
“
Anac.
“
“
“
Scientific name
Drypetes natalensis
Croton pseudopulchelis
Bridelia micrantha
Suregada zanzibarensis
Mallotus opposifolius
Euphobia nyikae
Flueggia virosa
Steculia rhynchocarpa
Ehretia petioleris
Euclea schimperi
Euclea racemosa
Diospyros consolatae
Encephalatos hildebrandtii
Vernonia zanzibarensis
Psiadia arabica
Terminalia boivanii
Mytenus mossambicensis
Mystrixylon aethiopicum
Markhamia zanzibarica
Cussonia zimmermanii
Mkilua fragrans
Annona senegalesis
Sorindeia madagascariensis
Rhus natalensis
Ozaroa obovata
Lannea schweinfurthii
Mimusopsis fruitcosa
Local name
Mjafari
Mfusho
Mkarati
Mdimu msitu
Mtumbika
Mkweche
Mkwamba
Muoza
Mtukutu
Mdaa
Msiliza
Mkururu
Mgwede
Mtumbaku mwitu
Mbebeta
Mkunguni
Muwanga
Mnusi
Mlimbo
Mtalawanda
Mpapai mwitu
Mchofu
Mtopetope
Mpilipilidoria
Mkumba
Mng’ombe
Muumbu
Mnyevuu
Legu.
Fern.
“
Dich.
Rub.
“
“
“
Til.
Sapot.
Sapind.
“
“
‘’
Papil.
Combre.
Pitt.
Ole.
Myrt.
Myrs.
Mora.
“
“
Melia.
“
Log.
Ican.
Flac.
Dichrostachys cinerea
Nephrolepis biserrata
Lomariopsis warneekei
Tapura fischeri
Psychotria goetzei
Tarenna pavettoides
Psychotria bibracteafum
Pohysphaeria parvifolia
Grewia spp.
Sideroxylon inarmis
Macphersonia gracilis
Dodonea viscosa
Blighia unijugata
Allophyllus spp.
Bysocarpus ovicutalis
Pittosparum viridiflorum
Olea woodiana
Eugenia spp.
Rapanea melanophlveas
Ficus sur
Ficus natalensis
Ficus lutea
Turrea floribunda
Bersama abyssinica
Strychnos angolensis
Apodyles dimidiata
Dovyalis macrocarly
Synaptolepis kirkii
Rhoicissues revoilii
Delbergia spp.
Teclea simplicifolia
Sansevieria conspicua
Todalia assiatica
Syzgium cumini
Lactana camara .
Clerodendron
Mvunja shoka/Mgunga
Mjimbi kuti
“
Mtama mwitu
Mti mafuta
Mchambelele
Mkonge
Mla paa
Mkole
Mkoko bara
Mjoma
Mkengeta
Mkuu Kilemba
Mchambelele
Mpaava
Muwanga
Mpande
Mlimbo
Mkaaga
Mkangala shamba
Mkuyu
Mla ndege
Mlangawa
Mtamagoa
Mwangwa kao
Mvuje msitu
Muwongoti
Mtumbua
Mbibikiu
Mtongo
Mvyongozi
Mvundo vundo
Katani pori
Mdaka komba
Mzambarau